Fitting hydrotherapy and hot tub appliances with ordinary water jet units or retrofitting older units, not so equipped, with the water jet devices is well known in the art. During the preparation of this disclosure an extensive search was performed in order to discover the relevant prior art that obtains in this particular field. Pertinent United States patents discovered were: U.S. Pat. Nos. 4,523,340 (Watkins, 1985); 4,546,505 (Wakenshaw, 1985); 4,304,740 (Cernoch, 1981); and 4,383,340 (Braun, Jr, 1983).
The patent issued to Watkins is the most pertinent of those discovered. Watkins teaches a "bubble" therapy that is employed in the instant invention. The Watkins water jet comprises a buoyant nozzle which simply adds air to an exhaust water stream to form a frothy ejecta for a hydrotherapy tub. The mechanism used to mix the air and water in the Watkins invention is essentially an ejector apparatus, a subject also well known in the art. Watkins employs a flexible air tube to introduce air into the outer cylindrical chamber of a nozzle. As the liquid motive fluid passes out of its source into the chamber, it entrains the air, lends a higher degree of buoyancy to the chamber which, in turn, rises in relation to the water level of the hydrotub and throughout the ejection operation is ejected as an air/water mixture from the rising and descending chamber. The novel aspect of the Watkins invention is the means and manner whereby the invention's exhaust water tube undulates as it expels the air/water mixture.
The invention of Wakenshaw is relevant in that the air/water mixture which it ejects is allowed to egress through a plurality of ports that are situated in groove-like conduits that run principally along the bottom of the tub. Whereas the Watkins invention inculcated moving apparatus as its principal feature, the Wakenshaw invention has no moving parts in its ejection mechanism. Wakenshaw however differs significantly from the invention of the instant inventors in that the air/water ejecta of Wakenshaw is emitted entirely below the water level of the tub. Further, Wakenshaw is primarily concerned with the portability of an inflatable spa and gives no particular attention to the groove-like conduits of the tub.
The Liquid Aeration apparatus of Cernoch is significant in that, in this apparatus, the air ejector principle is employed by an underwater jet of water entraining air through a snorkle-like device, i.e., the source of air is distinct from the source of water and, moreover, is located above the water level of the tub. To a small degree, this invention appears to employ one of the functional aspects of the instant inventors'.
The retrofit apparatus of Braun can more appropriately be described as an appliance for creating a whirlpool bath which is fitted into an existing tub space. The significant aspect of the Braun teaching is the use of a semi-tubular recessed surface intersecting a wedge-shaped recessed surface in the tub shell (that is to be) fitted into the original tub space. Further, the apertures are receptive of water jet nozzles that are designed to enhance the pressure and turbulence of water flowing from those nozzles and to distribute the turbulent water against the back of a person reclining against the supportive surfaces. Conspicuously absent from the invention and the teaching thereof is any expression or implication that the apertures or recessed surfaces act, or cooperate with the body, or function in any manner than that of mere channels. It is at this point, with the Braun disclosure as well as the aforementioned pertinent inventions, that the instant inventors would distinguish and disclose their novel hydrotherapy massage unit which may be built integrally with a hydrotherapy tub appliance or retrofitted to any existing tub appliance.
At the time of the instant invention, the inventors, designers and producers of hydrotherapy tubs, hot tubs and auxiliary equipment, determined that there existed in the applicable field no simply constructed, easily fitted or retrofitable froth/bubble ejector unit. Further, but for the placement of the human body within proximity of a water jet, there has been no teaching that the human body might in some way be employed cooperatively so as to acquire a therapeutic value from an inexpensive, simply constructed bubble massage unit.